5. 3 Operation, Performance and Maintenance of PV Systems
Monitoring, PV Modules, Defects, Reliability
Summary / Abstract:
For optimization of operation and maintenance of PV power stations the knowledge (identification and localization) of poor-performing modules, strings and inverters is important. The developed self-referencing method analyzes monitoring data, with a particular focus on energy yield. First, a well-performing unit is identified, second, the other units are set into relation to the well-preforming unit. Without weather data and prior-knowledge of the PVsystem poor-performing units (strings, inverters) are identified in this fashion. Three case studies are presented. IRimages verified the failure types. Strings suffering from yield loss due to PID or bridged PV-modules where identified and the yield loss quantified. Strings in bottom rows perform less (-2.6%) than those in top rows. The noise is about 4%, which means, failures with power loss less than 4% are masked in the uncertainty level of the monitoring data, e. g. one bypassed substring, hot cells. Yield relevant module failures such as PID, bridged modules, several bypassed substrings, are identified and localized reliably using the self-referencing method.